Portable spring powered infusion device having escapement means controlling speed ofinfusion



May 21, 1968 w. F. MULLER 3,384,080

PORTABLE SPRING POWERED INFUSION DEVICE HAVING ESCAPEMENT MEANS CONTROLLING SPEED OF INFUSION Filed Oct. 16, 1964 5 Sheets-Sheet l INVENTOR WOLF E MULLER RNEY y 1, 1968 w. F. MULLER 3,384,080

PORTABLE SPRING POWERED INFUSION DEVICE HAVING ESCAPEMENT MEANS CONTROLLING SPEED OF INFUSION 5 Sheets-Sheet b Filed Oct. 16, 1964 INVENTOR WOLF E MULLER May 21, 1968 w MULLER 3,384,080

PORTABLE SPRING POWERED INFUSION DEVICE HAVING ESCAPEMENT MEANS CONTROLLING SPEED OF INFUSION Filed Oct. 16, 1964 5 Sheets-Sheet 3 ENToR NEY United States Patent PORTABLE SPRING POWERED INFUSION DEVICE HAVING ESCAPEMENT MEANS CONTROLLING SPEED OF INFUSION Wolf F. Muller, New York, N.Y., assignor, by mesne assignments, to United States Catheter & Instrument Corporation, Glens Falls, N.Y., a corporation of Delaware Filed Oct. 16, 1964, Ser. No. 404,425 4 Claims. (Cl. 128-214) ABSTRACT OF THE DISCLOSURE A portable infusion device for constantly injecting therapeutic fluids into the human body at low but positive pressures, which has a roller pump squeezing tubing containing medicaments for injection into the body. The pump is powered by a spring motor, the speed of which is controlled by a watch escapement unit connected by gearing to the spring motor.

This invention relates to new and useful improvements in portable infusion devices and more particularly seeks to provide a low pressure, positive force portable infusion device adapted especially for ambulatory intravascular drug therapy over an extended period of time, e.g. arterial infusion of antimetabolite drugs for regional chemical therapy of cancer.

A huge undertaking of cancer research is currently in progress to develop anticancer drugs for use in the management of neoplastic disease in man and an in creasing number of compounds are becoming available for clinical use by the physician. Despite the prodigious efforts of these pre-clinical and clinical programs, progress has been slow and no chemical agents have been developed that are capable of inducing a general curative eifect on disseminated forms of cancer. Nevertheless, over the past several years definite advances have been made in the introduction of new chemical compounds and special techniques and procedures of their administration for the chemical control of advanced cancer.

Methods of regional cancer chemotherapy have been developed to enhance the antitumor effect of compounds currently in use which, when given systemically, have been shown to have little practical value in the management of certain localized, yet uncontrolled, forms of cancer. A catheter is inserted into the accessible blood supply of the neoplasm and an antimetabolite is administered by continuous infusion for 1 week to 4 months or longer. For the most part, antimetabolites have been investigated by this method of administration, alone, and at times, combined with the appropriate metabolite administered systemically. The largest clinical experience has been with the antifolic compound, Methotrexate, and its antidote, citrovorum factor, as well as with the fluorinated pyrimidines, FU and FUDR. In general, when the disease has been limited to the area of infusion, the results have been good in terms of objective tumor regression and sustained clinical benefit. Antidote of the anti metabolite may be administered systemically to counteract distant toxic actions on bone marrow and intestine.

It is also apparent that these newer local techniques will become significant both in the research study of endocrine system function and in the therapy of endocrine disease. The ability to infuse a vascular bed bearing a target organ over a period of days gives one the ability to control the internal enviornment of that organ. Known concentrations of durgs can be introduced directly into vascular channels leading to the gland and chronic intermittent sampling of the venous drainage is possible.

It is desirable to prolong current forms of regional cancer infusion therapy by the use of mechanism per mitting, on ambulatory, outpatients basis, parenteral ad ministration of fluid containing antimetabolite drugs Such a mechanism would also prove valuable in the ani mal laboratory since it would permit the continuou: parenteral infusion of drugs into unrestrained large ani mals, such as dogs.

In developing a mechanism for vascular infusion 0 other medical purposes, the output must be accurate, a low pressure and volume but at suflicient positive pres sure to prevent backflow on the high systolic point 0 the blood pressure. For ambulatory, out-patient use, thr mechanism must be light, simple, durable, dependablr and entirely selfcontained including the driving mecha nism.

To maintain sterile conditions and maintain acceptabl surgical techniques, the unit must be operable on a mini mum of instructions to patients, not subject to break down, and readily transferrable'to new patients withou danger of contamination. There must be high torque slow revolution but overdrive to fill the unit in the be ginning, and only uncostly disposable members that con tacts the medicament.

As disclosed hereinafter, the instant infusion devic meets all these demands and requirements. A small por table unit attachable to a catheter contains a replenish able drug supply, positive pump driving means at lot pressure and volume, easily and accurately measure output, and manual means for replenishing the powe means.

With these features in View, the nature of which wil be more apparent, the invention will be more fully under stood by reference to the drawings, the accompanyin detailed description, and the appended claims.

In the drawings:

FIG. 1 is a perspective view of the empty case from the medicament side;

FIG. 2 is a perspective view of the empty case from the driving side;

FIG. 3 is a plan view of the medicament side of th infusion device with all parts in position except the cover FIG. 4 is a plan view from the opposed driving side FIG. 5 is a section taken along line 5-5 of FIG. 3

FIG. 6 is a perspective exploded view of the drivin mechanism of FIG. 5

FIG. 7 is a perspective view of the tubing part1 mounted in the arcuate track segment;

FIG. 8 is a plan view with a plate removed of th watch braking mechanism;

FIG. 9 is a perspective view of the winding key;

FIG. 10 and 10a are side and plan views respectivel of the priming key;

FIG. 11 is a diagrammatic longitudinal section of th reservoir; and

FIG. 12 illustrates the filling of the reservoir.

As illustrated, this pump is designed primarily fo precisely injecting small volumes of parenteral fluid dur ing ambulatory intravascular therapy but obviously wit' or without modification may be used for many othe purposes, including precise feeding during space flight: precise feeding for animal experiments, etc.

A rectangular cast aluminum case 50 has an irregu lar partition 49 dividing a medicament chamber 39 cov ered by an inner cover not shown from a driving cham ber 55 covered by an outer cover not shown, the cas having dimensions of about 5" x 2.25" x 1325" an weighing about 340 gnarns when completed as describe hereinafter. The drug reservoir 53 is located in medic: ment chamber 39 and the clock escapement mechanisr 54 is in driving chamber 55, whereas the drive mecha nism is rotatably mounted in aperture 16 and is thu iositioned in both chambers. The covers are, of course, eadily removable by screws or otherwise.

The drive mechanism includes a mains rin g 17 mounted ind secured within cylinder 18 and secured at the other :nd to the winding hub 19 which is integral with base atchet plate 41 and spindle 61. The base ratchet plate nay be wound counterclockwise against the mainsp-ring ll'lCl is held from rotating clockwise by pawl 56 held in :osition by spring 57. Accordingly, the mainspring drives he cylinder 18 and associated gear 42. The gear 42 :arries an enlarged hub 43 rotatably mounted on spinlle 61 and a small ratchet 44. Rotatably mounted on hub i3 is a rotor including a smooth plate 46 spaced from rear 42 by a cylindrical wall 45 to enclose ratchet 44 ind to carry a pawl 59 so that plate 45 can move only n the direction of gear 42. The rotor also includes four :pindles 47 carried by plate 46 which terminate at their )pposecl ends in a priming gear 48. Rotatably mounted etween plate 46 and gear 48 on spindles 47 and exending beyond the periphery thereof, are four nylon -ollers 22 which are spaced about /32" from segment 23 for about 180 of plate 46 and gear 48 circle.

This segment 23 holds a short segment of silastic tubmg 24 which passes from the plastic drug reservoir 53 Jy the pump rollers to deliver fluid to the catheter atached to a subject. It may be provided at one end vith a hypodermic needle connector for puncture of a 'ubber diaphragm of the silastic drug reservoir, e.g. of ml. volume, and at the other end with a conventional nale Luer-lok or other connector for a catheter or other member. The tubing is fabricated with a solid ridge 26 rlon its outer side with a bore 27 for passage of the lrug. This solid ridge is clamped firmly into the semi- :ircular metal track segment 23 to prevent slippage of he tubing as the rotor revolves. The track is fabricated )f two semi-circular segments of metal which are screwed .ogether and held in accurate alignment by studs 29, single screw 31, and crown 62 on aperture 16. Loosening )f the holding screws permits slight separation of the ;wo semi-circular segments and introduction of the solid ridge of the silastic tubing into the track.

The tubing 24 is provided with a grommet 32 that is iecured to a notch in the casing Wall to prevent any :xternal force from pulling the tube out of position. Starting slightly proximal to the grommet and extending :o the peripheral end, the tubing is much thicker so that t will not reflect pulsations of the vascular system. At .he proximal end of ridge 26 is located an enlarged bead 53 which is used to longitudinally position the tubing 24 relative to the track segment 23. The track-retaining screw 31 0f the housing may be loosened sufificiently to pernit introduction of the tubing 24 and metal track 23. The semi-circular metal track must pass beneath the upper flange of the retaining posts 29 at either end of the groove in the easing into which the semi-circular track fits. it should be possible to completely advance the track retaining screw so that the semi-circular metal track gasses beneath each flange, thereby insuring that the pump will function by occlusive compression of the tubing by ;he pump rotors.

The rotor unit can rotate only counterclockwise under force of the mainspring or by positive force applied to :he priming gear 48 as shown hereinafter. The rotor unit s driven ordinarily by the mainspring through gear 4-2, :he speed of which is controlled by the clock escapement nechanism. Gear 42 drives first spur gear 64 which drives tecond spur gear 66 which drives third spur gear 67. [he third spur gear drives the escapement wheel con- .rolled by the escapement arm 36 and the balance wheel 54. This is a conventional clock escapement with two novements of the arm permitted per second. This is ranslated through appropriate gear reduction so that the 'otor makes a complete 360 revolution every hour which neans that the volume of fluid pumped per hour is four vimes the internal bore volume of 90 of the tubing. The

tubing is carefully calibrated to give, for example, 0.05 cc. per or 0.2 cc. per hour or 4.8 cc. per day.

It will be obvious that the amount of drug to be pumped can be varied by changing speed of the watch mechanism, changing bore of the tubing or changing concentration of material in the bag, the latter being generally the most convenient.

The proximal end of tube 24 may be provided with a knurled and threaded penetrating needle 25 which is particularly adapted for a leak-proof connection with reservoir 53. Various types of reservoirs could be used but that shown herein has been found preferable. This bag has molded within the outlet end a metal disc 68 with an internally threaded aperture 69 within an outwardly extending hub '71 and channel 72. Into this channel and also bulging outwardly is an integral part of the bag plastic to form a sealing hub 73 whereby the needle flange 7 is threaded down to provide a leak-proof secondary seal, there being a primary seal inside the bag where the needle point penetrates the internal plastic layer of the bag. The inlet or filling end of the bag includes a metallic collar 76 with partly circular and partly straight flange '77, a threaded aperture '73, a sealing hub 79 extending beyond the collar 76 and a plastic screw cap 81 which threads down to make a positive seal with hub 79.

It is desirable that the bag 53 be filled completely so that no air can be introduced into the system. This is done by holding the bag with holder 82 and introducing the medicament to the bottom with a syringe 83 as shown in FIG. 12. When the bag has been com pletely filled, the screw cap is threaded into aperture 78 before the bag is touched manualiy. If the bag is touched before closing, some squeezing will occur which diminishes the bag volume and subsequently draws air into the bag.

These filled bags may be provided to the patient as disposable units to be discarded after a single use or they may be returned for refilling. in either event, there should be no leakage into the housing or contamination thereof.

Once needle 25 has been properly inserted in bag 53, it is necessary to fill the line through tubing 24 and an attached catheter or it may be necessary to flush the line with saline. Since the rotor unit rotates once per hour, this is not practical. However, priming key 37 is placed in aperture 34 of plate 36 to connect with priming gear 48 whereupon the rotor may be advanced at will for priming or flushing purposes.

The winding key 38 or stem threads into winding hub 19 to tighten the mainspring 17 to force gear 42 counterclockwise against the speed control of the clock escapement mechanism. Both the priming and winding keys are detachable. The mainspring is generally calculated to run twelve hours it completely Wound. In any event, the patient can hear the ticking of the clock mechanism and will then know when the unit must be rewound.

The pump tubing (with attached metal track and adapters) and the disposable plastic drug reservoirs are the only parts of the device which need to be sterilized. Generally the tubing and reservoir will both be discarded when changing pumps from one patient to another so that the metal segment 23 is the only part that requires sterilization.

A harness is available so that the device can be strapped to the front of the chest. The winding hub 19 is directed outward so that the winding stem can be inserted without removal of the device from the harness case.

Iclaim:

1. A small-volume, positive-pressure, self-contained infusion device intended to be carried on the human body and adapted for constantly and slowly infusing desired liquids into the vascular system comprising a housing, an arcuate inflexible member secured inside said housing, an arcuate segment of flexible tubing mounted on the in ner surface of said arcuate inflexible member and adapted to be attached to a liquid reservoir and a catheter at the opposite ends thereof, a rotor mounted with its periphery parallel to and spaced from said arcuate inflexible memher, a plurality of rollers mounted on the periphery of said rotor and extending outward to a point adjacent said inflexible member, a tooth gear operably engaged with said rotor, a convolute mainspring operably engaged to drive said gear, means to wind said spring, and a watch escapement unit driven by said gear to control the speed thereof.

42. The device of claim 1 additionally comprising said reservoir positioned within said housing.

3. The device of claim 1 wherein said rotor includes a ratchet mechanism permitting rotation of one portion manually in order to prime or flush said tube.

4. The device of claim 1 additionally comprising a primary crank for manual rotation of said rotor and a winding crank to wind said mainspring.

References Cited UNITED STATES PATENTS Harris 222--7 Moulinier 103-14 Gilmore 222-9 Tomlinson 12821 Grau 128-214. Cherkin 128-21 Hahn 103-15 Wiley 222-7 France.

DALTON L. TRULUCK, Primary Examiner. 

